The mainline 5.11 patch "phy: rockchip: set pulldown for strobe line in dts" https://github.com/torvalds/linux/commit/8b5c2b45b8f0a11c9072da0f7baf9ee986d3151e (not backported to 5.10.y) seems to have broken most if not all rockchip board EMMC HS400 enhanced strobe support.
This probably affects supported rockchip boards (at least rk3399 ones, but probably most).
That is boards exhibit:
[ 18.985162] mmc1: running CQE recovery
[ 18.988056] ------------[ cut here ]----------